A/B Page Array Testing, in my mind, is an extension of the current A/B testing which Google Website Optimizer (GWO) already supports. Currently, GWO A/B tests are performed on a single page that one wants to optimize, a landing page, because landing page optimization (LPO) is the name of the game. But there are situations that can arise when multiple pages are tightly connected. An example I have in mind is a page with tabs, say the landing page has x tabs at the top of the page, which link to x pages of relevant information to the landing page.
Now, if you want to make alternative pages of each tab, and test which array of pages has a greater conversion rate, it's very difficult, but I would love it to be dumb dumb easy.
If this is a test you are interested in running, currently, the way I recommend you set it up is to setup a GWO Multivariate Test (MVT), where each page is a section. However, this will mean every combination of the sections and variations will be tested, which is more combinations than you would want to test, so you simply need to prune the undesired combinations.